Stress exposure in specific growth periods associates with children's weight, height, and body mass index.

Objectives: We investigate associations between children exposure to stressful events, considering: (1) the period in which the event took place, (2) the type of event, and (3) the cumulative effect of the events on children's weight, height and body mass index (BMI).

Methods: A total of 8429 Portuguese children (3349 exposed to at least one stressful event during their lifetime; 50.2% males; mean age = 7.21 ± 1.85 years) were included in the analysis. The occurrence of stressful (i.e., adverse) events was reported in a parental questionnaire; children's weight and height were objectively measured.

Results: When the stress event took place in the first 2 years of life, compared with during pregnancy or after the 2 years, children were shorter; but the association was weak and only significant for boys. After adjustment for child's birthweight, gestational age, breastfeeding duration, number of siblings, and father's education, the experience of 3+ stressful events (vs. 1 or 2) was associated with higher weight and height in boys. No interaction effect was found between stress and BMI.

Discussion: We found some evidence of associations between exposure to stressful events and physical growth of boys. We highlight the complex relationship between exposure to stressful experiences and children's physical growth, particularly the different effects of specific characteristics of the stress event and the sex differences.